Patent application title: LIGHT PIPE ASSEMBLY

Abstract:

A light pipe assembly includes a lamp assembly and a light pipe. The lamp
assembly has a housing that holds a light source configured to emit
light. The light pipe is elongated between an attachment end and an
opposing distal end. The attachment end is received in the housing of the
lamp assembly. The light pipe receives light emitted by the light source.
Additionally, the light pipe includes surface elements that are
configured to permit the light to emanate from the light pipe between the
attachment and distal ends. The surface elements are arranged in a
pattern that provides a predetermined distribution of light emanating
from the light pipe.

Claims:

1. A light pipe assembly comprising:a lamp assembly having a housing that
holds a light source configured to emit a light; anda light pipe
elongated between an attachment end and an opposing distal end, the
attachment end received in the housing of the lamp assembly, the light
pipe receiving light emitted by the light source, the light pipe
including surface elements configured to permit the light to emanate from
the light pipe between the attachment and distal ends, wherein the
surface elements are arranged in a pattern that provides a predetermined
distribution of light emanating from the light pipe.

2. The assembly of claim 1, wherein a distribution of the surface elements
in the pattern proximate to the attachment end differs from a
distribution of the surface elements in the pattern proximate to the
distal end.

3. The assembly of claim 1, wherein the surface elements are individual
surface elements separated from one another.

4. The assembly of claim 1, wherein a size of the surface elements in the
pattern proximate to the attachment differs from a size of the surface
elements in the pattern proximate to the distal end.

5. The assembly of claim 1, wherein a spatial density of the surface
elements in the pattern proximate to the attachment differs from a
spatial density of the surface elements in the pattern proximate to the
distal end.

6. The assembly of claim 1, wherein the light pipe is oriented along a
longitudinal axis and the surface elements comprise elongated strips
oriented transverse to the longitudinal axis.

7. The assembly of claim 6, wherein the surface elements comprise the
strips interconnected with one another in a direction along the
longitudinal axis.

8. The assembly of claim 1, wherein the surface elements comprise light
scattering elements disposed on an outer surface of the light pipe.

9. The assembly of claim 1, wherein the lamp assembly comprises a housing
having a mating portion that is configured to be coupled with the
attachment end of the light pipe, the attachment end having orientation
features to orient the distribution of light emanating from the light
pipe in a predetermined direction with respect to the lamp assembly.

10. A light pipe assembly comprising:a lamp assembly including a housing
and a light source, the housing having a mating portion, the light source
configured to emit light; anda light pipe elongated between an attachment
end and an opposing distal end and configured to receive light emitted by
the light source, wherein the attachment end is coupled with the mating
portion of the housing and includes orientation features to align the
light pipe with respect to the housing and to secure the light pipe to
the housing.

11. The assembly of claim 10, wherein the orientation features of the
attachment end inhibits rotation of the light pipe with respect to the
housing.

12. The assembly of claim 10, wherein the orientation features prevent
removal of the light pipe from the housing in a direction parallel to a
longitudinal axis of the light pipe.

13. The assembly of claim 10, wherein at least one of the mating portion
of the housing and the attachment end of the light pipe includes a notch
and the other one of the mating portion and the attachment end includes a
step, the step and notch shaped to nest with one another to align the
light pipe with respect to the housing.

14. The assembly of claim 10, wherein at least one of the mating portion
of the housing and the attachment end of the light pipe includes a latch
and the other of the mating portion and the attachment end includes a
slot, the latch received in the slot to prevent removal of the light pipe
from the housing in a direction parallel to a longitudinal axis of the
light pipe.

15. The assembly of claim 10, wherein the light pipe comprises surface
elements configured to permit the light to emanate from the light pipe
between the attachment and distal ends, wherein the surface elements are
arranged in a pattern that provides a predetermined distribution of light
emanating from the light pipe.

16. The assembly of claim 15, wherein the surface elements are positioned
on the light pipe such that the light emanating from the light pipe
through the surface elements is approximately uniform along the
longitudinal axis of the light pipe.

17. The assembly of claim 15, wherein at least one of a size and a spatial
density of each of the surface elements increases as a gradient between
the attachment and distal ends of the light pipe.

18. A light pipe assembly comprising:a lamp assembly having a housing that
holds a light source configured to emit light; anda light pipe extending
between an attachment end and an opposing distal end, the attachment end
received in the housing of the lamp assembly, the light pipe receiving
light emitted by the light source, the light pipe including
light-reflective surface elements that reflect the light received by the
light pipe in directions out of the light pipe between the attachment and
distal ends, wherein the surface elements include a plurality of
reflective strips interconnected by a reflective line.

19. The assembly of claim 18, wherein the reflective strips are disposed
transverse to a longitudinal axis of the light pipe and the reflective
line is disposed approximately parallel to the longitudinal axis.

20. The assembly of claim 18, wherein the surface elements are arranged on
the light pipe to provide an approximately even distribution of light
intensity on a surface that is angled with respect to the light pipe.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]This application claims the benefit of co-pending U.S. Provisional
Patent Application No. 61/070,277 filed Mar. 20, 2008, the subject matter
of which is herein incorporated by reference in its entirety

BACKGROUND OF THE INVENTION

[0002]A light pipe is a typically cylindrical, transparent structure
through which light is channeled or transmitted along the longitudinal
axis of the light pipe by total internal reflection. Total internal
reflection prevents the light from passing from inside the light pipe to
outside of the light pipe. Total internal reflection occurs when light
impinges on an interface between the light pipe and the atmosphere
surrounding the light pipe at an angle that is greater than a critical
angle. The critical angle is a function of the indices of refraction for
the medium of the light pipe and the medium of the surrounding
atmosphere.

[0003]The light transmitted by light pipes is generated by a light source.
The light source is usually contained in a lamp assembly to which the
light pipe is fastened. A typical lamp assembly includes a housing that
contains a light source such as a light emitting diode ("LED"). The light
pipe should be secured to the lamp assembly to prevent accidental
separation of the light pipe from the lamp assembly. In many applications
where light pipes are used, the space to accommodate the light pipe and
associated lamp assembly is limited. For example, the space available for
the light pipe and lamp assembly in interior automobile lighting may be
limited. Therefore, typically very little space is available for
structures and features that secure the light pipe to the lamp assembly.
Current known securing structures include mechanisms such as clamps and
epoxies. But, because the light pipe typically has a smooth, cylindrical
exterior, the light pipe may easily disconnect from a lamp assembly when
known securing structures are used to secure the light pipe to the lamp
assembly.

[0004]Known light pipes include a white strip or other surface element on
the light pipe or inside the light pipe that reflects light impinging on
the surface element. At least some of the reflected light strikes the
interface between the outside surface of the light pipe and the
surrounding atmosphere at an angle that is less than the critical angle
of the light pipe-atmosphere interface. This light emanates from the
light pipe as emitted light. In order to direct the reflected light in
the proper direction, the strip or surface element need to be properly
aligned with respect to the lamp assembly.

[0005]As the light emanates from the light pipe, the intensity of the
emitted light may decrease along the length of the light pipe. For
example if too much light escapes from the light pipe in locations near a
light source, the light emanating from an opposing end of the light pipe
may not be as bright or intense as the light emanating from other parts
of the light pipe. Such an uneven distribution of emitted light may be
undesirable.

[0006]Thus, a need exists to provide a light pipe that more evenly emits
light along the length of the light pipe. Moreover, a need also exists
for a coupling between the light pipe and lamp assembly that orients the
light pipe with respect to the lamp assembly.

BRIEF DESCRIPTION OF THE INVENTION

[0007]In one embodiment, a light pipe assembly is provided. The light pipe
assembly includes a lamp assembly and a light pipe. The lamp assembly has
a housing that holds a light source configured to emit light. The light
pipe is elongated between an attachment end and an opposing distal end.
The attachment end is received in the housing of the lamp assembly. The
light pipe receives light emitted by the light source. Additionally, the
light pipe includes surface elements that are configured to permit the
light to emanate from the light pipe between the attachment and distal
ends. The surface elements are arranged in a pattern that provides a
predetermined distribution of light emanating from the light pipe.

[0008]In another embodiment, another light pipe assembly is provided. The
light pipe assembly includes a lamp assembly and a light pipe. The lamp
assembly includes a housing and a light source. The housing has a mating
portion. The light source is configured to emit light. The light pipe
extends between an attachment end and an opposing distal end. The light
pipe is configured to receive light emitted by the light source. The
attachment end of the light pipe is coupled with the mating portion of
the housing and includes orientation features to align the light pipe
with respect to the housing and to secure the light pipe to the housing.

[0009]In another embodiment, a light pipe assembly includes a lamp
assembly and a light pipe. The lamp assembly has a housing that holds a
light source configured to emit light. The light pipe extends between an
attachment end and an opposing distal end. The attachment end is received
in the housing of the lamp assembly. The light pipe receives light
emitted by the light source and includes light-reflective surface
elements. The surface elements reflect the light received by the light
pipe in directions out of the light pipe between the attachment and
distal ends. The surface elements include a plurality of reflective
strips interconnected by a reflective line.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is an isometric view of a light pipe assembly in accordance
with one embodiment of the present invention.

[0011]FIG. 2 is a plan view of a pattern of surface elements and a graph
illustrating a gradient of the surface elements in the pattern in
accordance with one embodiment of the present invention.

[0012]FIG. 3 is a plan view of another pattern of surface elements
arranged in accordance with another embodiment of the present invention.

[0013]FIG. 4 illustrates a plan view of another pattern of surface
elements 402 and a plan view of the distal end of the light pipe shown in
FIG. 1 in accordance with another embodiment of the present invention.

[0014]FIG. 5 is a rear exploded isometric partial view of the light pipe
assembly shown in FIG. 1 implemented in accordance with one embodiment of
the present invention.

[0015]FIG. 6 is a front exploded isometric partial view of the light pipe
assembly shown in FIG. 1 according to one embodiment of the present
invention.

[0016]FIG. 7 is a front isometric view of a housing of a lamp assembly
shown in FIG. 1 according to one embodiment of the present invention.

[0017]FIG. 8 is an isometric cross-sectional view of a light pipe shown in
FIG. 1 attached to a lamp assembly shown in FIG. 1 taken along line 7-7
in FIG. 1 according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0018]FIG. 1 is an isometric view of a light pipe assembly 100 implemented
in accordance with one embodiment. The light pipe assembly 100 includes a
light pipe 102 and a lamp assembly 104. The light pipe 102 is elongated
along a longitudinal axis 110 between an attachment end 112 and a distal
end 114. The light pipe 102 may be formed from a light transmissive
material, such as an acrylic material. In one embodiment, the light pipe
102 is an extruded cylindrical rod formed of a translucent acrylic
material. Other shapes of the light pipe 102 may be used, including
shapes having bends or undulations in the general elongated shape of the
light pipe 102 shown in FIG. 1. The diameter or other cross-sectional
dimensions of the light pipe 102 may depend on the particular application
to which the light pipe 102 is used. For example, one or more embodiments
described herein may be particularly suitable for automotive applications
and For use with household appliances. Such applications may require
relatively small diameters of the light pipe 102.

[0019]The lamp assembly 104 includes a light source 106 held in a housing
108. The light source 106 includes one or more individual sources of
light that emit the light into the light pipe 102. For example, the light
source 106 may be a single light emitting diode or include a plurality of
light emitting diodes. A single light source 106 may include more than
one type of light generating component. The housing 108 may be formed
from a dielectric material such as a polymer. Alternatively, the housing
108 may be formed from a metal. The attachment end 112 of the light pipe
102 is received in the housing 108 to secure the light pipe 102 to the
lamp assembly 104 and to orient the light pipe 102 with respect to the
lamp assembly 104 such that light emitted by the light pipe 102 is
directed in a desired or predetermined direction. The light source 106
emanates light toward the attachment, end 112 of the light pipe 102. The
light is transmitted through the light pipe 102 generally from the
attachment end 112 toward the distal end 114.

[0020]A band or pattern 116 of individual surface elements 118 is provided
on the light pipe 102. The surface elements 118 may be separated from one
another such that the surface elements 118 are not interconnected with
one another. The surface elements 118 may be printed or otherwise adhered
to an outer surface 120 of the light pipe 102. Alternatively, the surface
elements 118 may be formed on the inside of the light pipe 102. For
example, the surface elements 118 may be formed inside the light pipe 102
as the light pipe 102 is extruded. In one embodiment, the surface
elements 118 reflect the light that impinges on the surface elements 118.
For example, at least some of the light that is transmitted through the
light pipe 102 may strike the surface elements 118 and be reflected or
scattered by the surface elements 118. The surface elements 118 reflect
the light and may cause the light to emanate from the light pipe 102 as
emitted light 122. The light 122 may emanate from the light pipe 102 in a
direction transverse to the longitudinal axis 110. The emitted light 122
may emanate from the light pipe 102 in a variety of directions, including
from a side opposing the surface elements 118. For example, the emitted
light 122 may exit the light pipe 102 in directions substantially
opposite the surface elements 118. In the example shown in FIG. 1, the
emitted light 122 includes light that emanates from a surface of the
light pipe 102 that is disposed 180 degrees from the surface elements
118, or on an opposite side of the approximately circular cross-sectional
shape of the light pipe 102.

[0021]The pattern 116 of the surface elements 118 may be provided along
the length of the light pipe 102 in one or more of a shape and
distribution in order to provide a desired distribution of the light 122
emanating from the light pipe 102. For example, the pattern 116 may cause
the surface elements 118 to reflect the light 122 out of the light pipe
102 in a projected distribution 124. The projected distribution 124 of
the light 122 is shown schematically in FIG. 1 and may take alternative
sizes and/or shapes. The projected distribution 124 may be defined by a
length 126 and a projection angle 128. The length 126 of the distribution
124 represents the distance along the light pipe 102 in a direction
parallel to the longitudinal axis 110 that the light 122 emanates from
the light pipe 102 in directions transverse to the longitudinal axis 110.
The projection angle 128 is the angle subtended by the distribution 124,
or the radial distance that the projection angle 128 extends over the
surface 120 of the light pipe 102.

[0022]Alternatively, the surface elements 118 may include light
transmissive elements having an index of refraction that differs from the
index of refraction of the light pipe 102. The interfaces between the
surface elements 118 and the light pipe 102 may alter the critical angle
required for total internal reflection. For example, the surface elements
118 may have an index of refraction that increases the critical angle at
the interface between the light pipe 102 and the surface elements 118.
Increasing the critical angle may reduce the amount of light that is
internally reflected in the light pipe 102 and may increase the amount of
light that emanates from the light pipe 102. The light that is refracted
by the surface elements 118 may emanate from the light pipe 102 through
the surface elements 118. For example, the emanating refracted light may
exit the light pipe 102 proximate the same side of the light pipe 102 on
which the surface elements 118 are disposed.

[0023]In one embodiment, the size and/or spatial density of the surface
elements 118 may change in the pattern 116. For example, the size and/or
spatial density of the surface elements 18 may increase in the pattern
116 between the attachment and distal ends 112, 114. The spatial density
of the surface elements 118 may be defined as the number of surface
elements 118 per unit of surface area of the light pipe 102. As described
below, the surface elements 118 located in the pattern 116 in locations
proximate to the attachment end 112 may be smaller, and/or the density of
the surface elements 118 may be less, when compared to the size and/or
spatial density of the surface elements 118 in locations proximate to the
distal end 114. By controlling the size and/or density of the surface
elements 118 in the pattern 116, the amount of emanated light 122 may be
controlled along the longitudinal axis 110 of the light pipe 102. For
example, less light may emanate from the light pipe 102 in locations near
the attachment end 112 where the surface elements 118 are smaller and/or
are provided in a lesser spatial density. The size and/or density of the
surface elements 118 increases along the longitudinal axis 110 of the
light pipe 102 toward the distal end 114, to compensate for the reduced
amount of light impinging on each surface element 118. For example, a
lesser amount of the light transmitted within the light pipe 102 may be
reflected by the surface elements 118 and emanate from the light pipe 102
near the attachment end 112 than the surface elements 118 near the distal
end 114. The size and/or density of the surface elements 118 may be
tailored to provide an approximately uniform distribution of light 122
emanating from the light pipe 102 along the longitudinal axis 110 between
the attachment and distal ends 112, 114. For example, the light 122 may
emanate from the light pipe 102 such that no appreciable gradient in the
intensity of the emitted light 122 exists.

[0024]FIG. 2 is a plan view of a pattern 200 of surface elements 202
arranged in accordance with one embodiment. The pattern 200 of the
surface elements 202 may be similar to the pattern 116 (shown in FIG. 1)
of the surface elements 118 (shown in FIG. 1). The pattern 200 may be
disposed on the curved outer surface 120 (shown in FIG. 1) of the light
pipe 102 (shown in FIG. 1). The pattern 200 extends between opposing ends
204, 206. In one embodiment, the pattern 200 may be disposed on the light
pipe 102 so that the first end 204 is located proximate to the attachment
end 112 and the second end 206 is located proximate to the distal end
114. An area on the outer surface 120 of the light pipe 102 between the
first end 204 and the attachment end 112 and/or between the second end
206 and the distal end 114 may not include any surface elements 202. For
example, the pattern 200 may extend along a length 208 that is less than
the distance between the attachment and distal ends 112, 114 in a
direction parallel to the longitudinal axis 110 (shown in FIG. 1).
Adjusting the length 208 of the pattern 200 may alter the length 126
(shown in FIG. 1) of the projected distribution 124 (shown in FIG. 1) of
the emanating light 122 (shown in FIG. 1). For example, increasing the
length 208 may increase the length 126 of the projected distribution 124
of light 122 while decreasing the length 208 may decrease the length 126
of the projected distribution 124.

[0025]The pattern 200 may extend along a width 212 in a direction
transverse to the longitudinal axis 110. The width 212 of the pattern 200
may extend around less than the entire outer circumference of the outer
surface 120 of the light pipe 102. For example, the width 212 may be
small enough such that multiple patterns 200 may be disposed around the
outer surface 120 of the light pipe 102. Alternatively, the width 212 may
extend around the entire outer circumference of the light pipe 102. In
one embodiment, the width 212 is approximately the same throughout the
length 208 of the pattern 200. In another embodiment, the width 212 may
vary across the length 208 of the pattern 200 to adjust the distribution
of the light 122 (shown in FIG. 1) emanating from the light pipe 102.
Adjusting the width 212 of the pattern 200 may alter the projection angle
128 (shown in FIG. 1) of the projected distribution 124 (shown in FIG. 1)
of light 122. For example, increasing the width 212 may increase the
projection angle 128 of the light 122. Decreasing the width 212 may
decrease the projection angle 128.

[0026]The spatial density of the surface elements 202 may increase
throughout the pattern 200 along the length 208 of the pattern 200.
Alternatively, the spatial density may change through only a portion, or
less than all, of the pattern 200. A graph 214 illustrates an example of
a gradient 216 that may represent the distribution or change in the
spatial density of the surface elements 202 in the pattern 200. The
horizontal axis 218 in the graph 214 represents the distance along a
length 208 of the pattern 200. The vertical axis 220 may represent the
spatial density of the surface elements 202 in the pattern 200. As shown
in FIG. 2, the spatial density of the surface elements 202 may change
throughout the pattern 200 according to the gradient 216. For example,
the gradient 216 may define the packing density of the surface elements
202 in the pattern 200. The gradient 216 represents the graded change of
the number of surface elements 202 provided in the pattern 200 per unit
area. In the example shown in FIG. 2, more surface elements 202 are
provided in the pattern 200 per square unit of surface area of the
pattern 200 in locations approaching the second end 206 than the first
end 204. In another example, the distance between one surface element 202
and the neighboring surface elements 202 may be greater towards the first
end 204 than the second end 206. While the gradient 216 is illustrated as
an straight line in FIG. 2, the gradient 216 may take the form of one or
more other shapes, such as a curved line or a combination of curved and
straight lines.

[0027]In one embodiment, the sizes of the surface elements 202 may
increase throughout the pattern 200 along the length 208 of the pattern
200. For example, the sizes of the surface elements 202 may be
distributed in the pattern 200 according to the gradient 216.
Alternatively, the sizes of the surface elements 202 may change through
only a portion, or less than all, of the pattern 200. In the embodiment
shown in FIG. 2, outside dimensions 210 of the surface elements 202
increase throughout the pattern 200 from the first end 204 to the second
end 206. The outside dimensions 210 may be the greatest distance
extending across the surface elements 202. By way of example only, the
outside dimensions 210 may be the outer diameters of the surface elements
202. In the illustrated embodiment, the outside dimensions 210 are
measured in directions parallel to the longitudinal axis 110 (shown in
FIG. 1) of the light pipe 102 (shown in FIG. 1). Optionally, only one of
the spatial density and the sizes of the surface elements 202 may change
throughout the pattern 200. For example, only one of the spatial density
and the sizes of the surface elements 202 may change in the pattern 200
according to the gradient 216. Alternatively, each of the spatial density
and the sizes of the surface elements 202 may change throughout the
pattern 200 according to different gradients 216.

[0028]FIG. 3 is a plan view of a pattern 300 of surface elements 302
arranged in accordance with one embodiment. 1The pattern 300 of the
surface elements 302 may be similar to the pattern 116 (shown in FIG. 1)
of the surface elements 118 (shown in FIG. 1). The pattern 300 may be
disposed on the curved outer surface 120 (shown in FIG. 1) of the light
pipe 102 (shown in FIG. 1). The pattern 300 extends between opposing ends
304, 306. In one embodiment, the pattern 300 may be disposed on the light
pipe 102 so that the first end 304 is located proximate to the attachment
end 112 and the second end 306 is located proximate to the distal end
114. The pattern 300 may extend along a length 308 that is less than the
distance between the attachment and distal ends 112, 114 in a direction
parallel to the longitudinal axis 110 (shown in FIG. 1). Adjusting the
length 308 of the pattern 300 may alter the length 126 (shown in FIG. 1)
of the projected distribution 124 (shown in FIG. 1) of the emanating
light 122 (shown in FIG. 1). For example, increasing the length 308 may
increase the length 126 of the projected distribution 124 of light 122
while decreasing the length 308 may decrease the length 126 of the
projected distribution 124. The pattern 300 may extend along a width 312
in a direction transverse to the longitudinal axis 110. The width 312 of
the pattern 200 may extend around less than or the entire outer
circumference of the outer surface 120 of the light pipe 102. Adjusting
the width 312 of the pattern 300 may alter the projection angle 128 of
the projected distribution 124 of light 122. For example, increasing the
width 312 may increase the projection angle 128 of the light 122.
Decreasing the width 312 may decrease the projection angle 128.

[0029]The pattern 300 is similar to the pattern 200 (shown in FIG. 2) in
that the size and spatial density of the surface elements 302 may
increase along the length 308 of the pattern 300. For example, one or
more of the sizes and spatial densities of the surface elements 302 may
change throughout all or less than all of the pattern 300 according to a
gradient that is the same as or similar to the gradient 216 (shown in
FIG. 2). One difference between the patterns 300 and 200 (shown in FIG.
2) is the shape of the surface elements 302 and 202 (shown in FIG. 2).
The surface elements 302 include elongated shapes having a height 314 and
a width 316. In the illustrated embodiment, the surface elements 302 are
strips defined by the height 314 and width 316 dimensions. The height 314
of the surface elements 302 may be measured in a direction that is
transverse to the longitudinal axis 110 (shown in FIG. 1) of the light
pipe 102 (shown in FIG. 1). For example, the height 314 of the surface
elements 302 may be measured in a direction parallel to the direction in
which the width 312 of the pattern 300 is measured. The width 316 of the
surface elements 302 may be measured in a direction that is parallel to
the longitudinal axis 110. Alternatively, the surface elements 302 may be
provided in a shape other than a strip. For example, the surface elements
302 may be provided as ovals, squares, triangles, and the like.

[0030]As shown in FIG. 3, the spatial density of the surface elements 302
increases throughout the pattern 300 along the length 308 of the pattern
200. For example, a separation distance 318 between adjacent surface
elements 302 decreases along the length 308 of the pattern 300. The
spatial density of the surface elements 302 increases as the separation
distance 318 decreases. Additionally, the sizes of the surface elements
302 increase throughout the pattern 300 along the length 308 of the
pattern 300. For example, the width 316 of the surface elements 202 may
increase throughout the pattern 300 from the first end 304 to the second
end 306. Alternatively, the width 316 may remain substantially the same
throughout all or at least some of the pattern 300. In another example,
the height 314 of the surface elements 202 may increase throughout the
pattern 300 from the first end 304 to the second end 306.

[0031]FIG. 4 illustrates a plan view 406 of another pattern 400 of surface
elements 424 and a plan view 408 of the distal end 114 of the light pipe
102 in accordance with another embodiment. A portion of the light pipe
102 is shown in FIG. 4. The light pipe 102 includes surface elements 424
that include strips 402 that are interconnected with one another by a
line 404. The line 404 may be a surface element 424 that is positioned
between the other strips 402 so as to interconnect the strips 402 with
one another. As shown in FIG. 4, the strips 402 are substantially linear
strips disposed in a direction transverse to the longitudinal axis 110 of
the light pipe 102. For example, the individual strips 402 may be
perpendicular to the longitudinal axis 110. Alternatively, the strips 402
may be positioned at an obtuse or acute angle with respect to the
longitudinal axis 110. Each of the strips 402 has a width dimension 418
that is measured in a direction parallel to the longitudinal axis 110 of
the light pipe 102. The width 418 of the strips 402 may be approximately
the same for all strips 402 in the pattern 400 or may vary throughout the
pattern 400 similar to as described above in connection with the patterns
116 (shown in FIG. 1), 200 (shown in FIG. 2), 300 (shown in FIG. 3). The
strips 402 are separated from one another by a separation distance 420.
The separation distance 420 may be measured in a direction that is
parallel to the longitudinal axis 110. The separation distance 420
between each pair of strips 402 may be the same or may vary throughout
the pattern 400.

[0032]The interconnecting line 404 extends along the light pipe 102 in a
direction that is transverse to the individual strips 402. For example,
the interconnecting line 404 may extend substantially parallel to the
longitudinal axis 110. Alternatively, the interconnecting line 404 may be
disposed at a transverse angle with respect to the longitudinal axis 110.
The interconnecting line 404 has a thickness dimension 422 that is
measured in a direction transverse to the longitudinal axis 110. For
example, the thickness 422 of the interconnecting line 404 may be
measured in a direction perpendicular to the longitudinal axis 110. The
thickness 422 may be approximately the same throughout the
interconnecting line 404 or may vary throughout the pattern 400.

[0033]The interconnecting line 404 connects the strips 402 such that the
strips 402 and line 404 form a continuous light scattering surface on the
light pipe 102. The surface elements 424 may cause light transmitted by
the light pipe 102 to exit the light pipe 102 as emanating light 410 in a
projection 412. The projection 412 of light 410 may provide for a more
even distribution of light intensity on a surface 414 that is angled or
sloped with respect to the light pipe 102. As shown in FIG. 4, the
surface 414 is disposed at an angle with respect to the light pipe 102.
In one embodiment, a normal direction 416 to the surface 414 is
transverse to the longitudinal axis 110 of the light pipe 102. The
position of the interconnecting line 404 in each of the views 406, 408 is
indicated by the phantom line labeled "a" and the positions of the strips
402 in the views 406, 408 are indicated by the phantom line labeled "b."
In the illustrated example, the interconnecting line 404 and strips 402
are disposed on the light pipe 102 such that the interconnecting line 404
is closer to the illuminated surface 416 than the strips 402.

[0034]Due to the continuous nature of the interconnecting line 404, or
that the interconnecting line 404 extends along the longitudinal axis 110
of the light pipe 102 so as to cover a greater total surface area than
the strips 402, the interconnecting line 404 nay reflect more light 410
out of the light pipe 102 than the strips 402. As a result, the light 410
that is reflected out of the light pipe 102 by the interconnecting line
404 may be more intense upon exiting the light pipe 102 than the light
410 reflected by the strips 402. The more intense light that is reflected
by the interconnecting line 404 may be directed toward the portion of the
angled surface 414 that is farther away from the light pipe 102 while the
less intense light that is reflected by the strips 402 may be directed
toward the portion of the angled surface 414 that is closer to the light
pipe 102. For example, the light 410 that is reflected out of the light
pipe 102 by the interconnecting line 404 may strike the surface 414 in
the illuminated area labeled "A" and the light 410 that is reflected out
of the light pipe 102 by the strips 402 may strike the surface 414 in the
illuminated area labeled "B." As shown in FIG. 4, the "A" area of the
surface 414 is farther away from the light pipe 102 than the "B" area. By
aligning the pattern 400 on the light pipe 102 and by aligning the light
pipe 102 with respect to the surface 414, the more intense light 410 that
is reflected by the interconnecting line 404 may be directed towards the
farther away area "A" of the surface 414 than the less intense light 410
that is reflected by the strips 402 and directed toward the closer area
"B" of the surface 414. Directing the reflected light from the pattern
400 in this manner may provide a more uniform distribution of the
intensity of the light on the surface 414.

[0035]FIG. 5 is a rear exploded isometric partial view of the light pipe
assembly 100 implemented in accordance with one embodiment. FIG. 6 is a
front exploded isometric partial view of the light pipe assembly 100
according to one embodiment. FIG. 7 is a front isometric view of the
housing 108 of the lamp assembly 104 according to one embodiment. As
shown in FIGS. 5 and 6, the housing 108 of the light pipe assembly 100
includes a mating portion 512 (FIG. 5) for attaching the light pipe 102
to the lamp assembly 104. The mating portion 512 includes an opening 500
(FIG. 6) into which the attachment end 112 of the light pipe 102 is
loaded to mount the light pipe 102 in the lamp assembly 104. An inside
dimension 502 (FIG. 6) of the opening 500 may be less than an outer
diameter 504 (FIG. 6) of the light pipe 102 to provide an interference
fit between the light pipe 102 and the lamp assembly 104. When the
attachment end 112 of the light pipe 102 is loaded into the mating
portion 512 of the housing 108, the opening 500 may expand to accommodate
the light pipe 102. One or more slits 514 (FIG. 5) in the mating portion
512 may be provided to permit expansion of the opening 500.

[0036]One or both of the light pipe 102 and the lamp assembly 104 may
include orientation features to align the light pipe 102 with respect to
the lamp assembly 104. Aligning the light pipe 102 with the lamp assembly
104 may permit the light emanating from the light pipe 102 to be directed
in a desired or predetermined direction. In one embodiment, the
orientation features that align the light pipe 102 with respect to the
lamp assembly 104 include a notch 518 (FIG. 5) in the light pipe 102 and
a step 510 (FIG. 6) in the lamp assembly 104. Alternatively, the notch
518 may be included in the housing 108 of the lamp assembly 104 and the
step 510 may be provided in the light pipe 102. The step 510 includes a
generally flat lip 600 (FIG. 7) along the inside of the step 510. The
notch 518 includes a recess in the attachment end 112 of the light pipe
102 that is shaped to mate with the step 510. The notch 518 may be formed
such that the cross-sectional area of the light pipe 102 in a section
that includes the notch 518 and that is measured in a plane perpendicular
to the longitudinal axis 110 is less than the cross-sectional area of the
light pipe 102 in a section that does not include the notch 518 and that
is measured in a plane perpendicular to the longitudinal axis 110.

[0037]The step 510 and notch 518 may have complimentary shapes such that
the step 510 and notch 518 nest with one another when the light pipe 102
is loaded into the housing 108. The engagement between the orientation
features of the light pipe 102 and the lamp assembly 104 limits or
inhibits rotation of the light pipe 102 with respect to the housing 108
of the lamp assembly 104. Preventing rotation of the light pipe 102 may
ensure that the pattern 116 of surface elements 118 is oriented in a
desired direction. For example, the notch 518 and step 510 may be
disposed in a desired location with respect to the pattern 116 in order
to direct the light 122 (shown in FIG. 1) emanating from the light pipe
102 along a desired direction or path.

[0038]In one embodiment, the orientation features secure the light pipe
102 to the lamp assembly 104. For example, the orientation features may
include a slot 516 (FIG. 5) in the light pipe 102 and a rib 506 (FIG. 6)
in the housing 108 of the lamp assembly 104. The slot 516 and rib 506 may
engage one another to prevent removal of the light pipe 102 from the
housing 108 in a direction parallel to the longitudinal axis 110 of the
light pipe 102. The slot 516 extends along the outer circumference of the
light pipe 102 near the attachment end 112. As shown in FIG. 5, the notch
518 and slot 516 in the light pipe 102 may be circumferentially offset
From one another along the outer surface 120 of the light pipe 102. The
slot 516 may include a front wall 800 and a rear wall 802 spaced apart
from one another in a direction parallel to the longitudinal axis 110.
The rib 506 may include a ramp surface 602 (FIG. 7) joined to a latch
surface 604 (FIG. 7). The ramp surface 602 may be positioned transverse
to the latch surface 604 and extend between an inner surface 508 (FIG. 6)
of the housing 108 and the latch surface 604. The latch surface 604 may
extend between the inner surface 508 and the ramp surface 602.
Alternatively, the ramp and latch surfaces 602, 604 may be positioned
parallel to one another with a third surface (not shown) interconnecting
the ramp and latch surfaces 602, 604. For example, the ramp and latch
surfaces 602, 604 may be parallel to one another and each extend between
the inner surface 508 and the third surface.

[0039]FIG. 8 is an isometric cross-sectional view of the light pipe 102
attached to the lamp assembly 104 taken along line 7-7 in FIG. 1
according to one embodiment. As shown in FIG. 8, the rib 506 is received
in the slot 516 between the front and rear walls 800, 802 to secure the
light pipe 102 to the housing 108 of the lamp assembly 104. The ramp
surface 602 slides along the front wall 800 of the slot 516 as the light
pipe 102 is loaded into the housing 108. The latch surface 604 engages
the front wall 800 to prevent removal of the light pipe 102 from the lamp
assembly 104. A depth 700 of the slot 516 represents the radial distance
that the slot 516 extends into the light pipe 102 from the outer surface
120 of the light pipe 102. A height 702 of the rib 506 represents the
distance that the rib 506 protrudes from the inner surface 508 of the
housing 108. The depth 700 of the slot 516 and the height 702 of the rib
506 may be approximately matched with one another such that the rib 506
is entirely received with in the slot 516. For example, the height 702 of
the rib 506 may be approximately the same as the depth 700 of the slot
516. A variety of materials may be used for the light pipe assembly 100
(shown in FIG. 1). For example, materials that are elastic enough to
allow insertion of the light pipe 102 into the housing 108 and provide a
sufficient retention force once the light pipe 102 is inserted therein,
and/or to expand and retract a sufficient amount to allow the light pipe
102 to be secured to the housing 108.

[0040]Dimensions, types of materials, orientations of the various
components, and the number and positions of the various components
described herein are intended to define parameters of certain
embodiments, and are by no means limiting and are merely exemplary
embodiments. Many other embodiments and modifications within the spirit
and scope of the claims will be apparent to those of skill in the art
upon reviewing the above description. The scope of the invention should,
therefore, be determined with reference to the appended claims, along
with the full scope of equivalents to which such claims are entitled. In
the appended claims, the terms "including" and "in which" are used as the
plain-English equivalents of the respective terms "comprising" and
"wherein." Moreover, in the following claims, the terms "first,"
"second," and "third," etc. are used merely as labels, and are not
intended to impose numerical requirements on their objects. Further, the
limitations of the following claims are not written in
means-plus-function format and are not intended to be interpreted based
on 35 U.S.C. §1102, sixth paragraph, unless and until such claim
limitations expressly use the phrase "means for" followed by a statement
of function void of further structure.